Prosopis strombulifera aqueous extract reduces T cell response and ameliorates type I diabetes in NOD mice.

Background: New products with tolerogenic properties on T cell response are necessary to improve current efficacy, cost and side effects of immunosuppressants. Prosopis strombulifera aqueous extract (PsAE) have reported cytotoxic, antitumoral, antiatherogenic and antileishmanial activities, containing phytochemicals with immune-related activities. Despite these, there are no previous studies with respect to PsAE suppressive properties over T cell proliferation and their function. Goal: Because of previous antecedents, this study aims to evaluate the effect of PsAE on T cell activation, proliferation, cytokine production, and to investigate its effect over an in vivo model of type 1 diabetes (T1D). Experimental procedure: Splenocytes and sorted CD4+/CD8+ from wild type C57BL/6 mice were cultured to determine activation, IFN-γ release and T-cell proliferation after polyclonal stimulation. NOD (non-obese diabetic) mice were used to study the effects of orally administered extract on glycemia, insulitis stages and perforin-1 (PRF-1)/granzyme-B (GRZ-B) expression. Results: In primary cultures, the plant extract impairs T cell activation, decreases IFN-γ release, and reduces proliferation after different polyclonal stimuli. In vivo, PsAE improves NOD mice glycemic levels and T1D progression by diminution of pancreas insulitis and reduction of PRF-1 and GRZ-B mRNA expression. To our knowledge, this is the first report characterizing the therapeutic properties of PsAE on T cell activation. Conclusion: The current work provides evidence about in vitro and in vivo immunosuppressive effects of PsAE and promotes this plant extract as a complementary and alternative treatment in autoimmune T-cell mediated diseases as T1D.

UHPLC-Q/Orbitrap/MS/MS fingerprinting and antitumoral effects of Prosopis strombulifera (LAM.) BENTH. queous extract on allograft colorectal and melanoma cancer models.

The aqueous extract of the Argentinean native plant, Prosopis strombulifera (PsAE), presents cytotoxicity against human cancer cell lines by inducing cytostasis, necrosis and apoptosis; with diminution of clonogenic survival; without genotoxic effects nor oral animal toxicity. Until now, the chemical extract composition and its in vivo antitumoral properties remain unknown; these studies are the aim of the current work. The PsAE was characterized by chemical fingerprinting and the metabolome was identified by tandem UHPLC-PDA-HESI-Q-orbitrap® mass spectrometry. Colorectal tumors were induced by DMH administration and melanomas resulted from B16-F0 S.C. cells injection; then, animals were treated orally with PsEA. To correlate in vivo results with in vitro cytotoxicity, B16-F0 cell were cultured to determine: cell proliferation and viability by dye exclusion assays, MTT and CFSE dilution; cell cycle distribution by flow cytometry; and immunoblotting of p21cip1, PCNA, cleaved caspase 3, cleaved PARP and TUBA1A. Based on UHPLC-OT-MS and PDA analysis, twenty-six compounds were identified, including: 5 simple organic acids, 4 phenolic acids, 4 procyanidins, 11 flavonoids, and 2 oxylipins. On C57BL6 mice, PsAE significantly increases the median survival on colorectal cancer and reduces the final volume and weight of melanomas. Over cultured cells, the treatment induce over-expression of p21, cytostasis by G2/M cell cycle arrest and apoptosis; while, on in vivo melanomas, treatment up-regulates p21 and slightly decreases PCNA. In conclusion, PsAE is composed by phenolic compounds which demonstrate cytotoxic and antitumoral properties when is orally administrated. Presented results support future research of PsAE as a potential phytomedicine for cancer treatment.

Hypothyroidism decreases JAK/STAT signaling pathway in lactating rat mammary gland.

Thyroid pathologies have deleterious effects on lactation. Especially hypothyroidism (HypoT) induces premature mammary involution at the end of lactation and decreases milk production and quality in mid lactation. Milk synthesis is controlled by JAK2/STAT5 signaling pathway and prolactin (PRL), which activates the pathway. In this work we analyzed the effect of chronic 6-propyl-2-thiouracil (PTU)-induced HypoT on PRL signaling pathway on mammary glands from rats on lactation (L) days 2, 7 and 14. HypoT decreased prolactin receptor expression, and expression and activation of Stat5a/b protein. Expression of members of the SOCS-CIS family, inhibitors of the JAK-STAT pathway, decreased in L2 and L7, possibly as a compensatory response of the mammary cells to maintain PRL responsiveness. However, on L14, the level of these inhibitors was normal and the transcription of α-lactoalbumin (lalba), a target gene of the PRL pathway, decreased by half. HypoT altered the transcriptional capacity of the cell and decreased mRNA levels of Prlr and Stat5b on L14. Stat5b gene has functional thyroid hormone response elements in the regulatory regions, that bind thyroid hormone receptor ß (TRß) differentially and in a thyroid hormone dependent manner. The overall decrease in the PRL signaling pathway and consequently in target gene (lalba) mRNA transcription explain the profound negative impact of HypoT on mammary function through lactation.

Hydroxytyrosol and oleuropein of olive oil inhibit mast cell degranulation induced by immune and non-immune pathways.

The aim of this study was to determine whether hydroxytyrosol and oleuropein, the major phenols found in olives and olive oil, inhibit mast cell activation induced by immune and non-immune pathways. Purified peritoneal mast cells were preincubated in the presence of test compounds (hydroxytyrosol or oleuropein), before incubation with concanavalin A, compound 48/80 or calcium ionophore A23187. Dose-response and time-dependence studies were carried out. Comparative studies with sodium cromoglycate, a classical mast cell stabilizer, were also made. After incubation the supernatants and pellets were used to determine the ß-hexosaminidase content by colorimetric reaction. The percentage of ß-hexosaminidase release in each tube was calculated and taken as a measure of mast cell activation. Other samples of cell pellets were used for cell viability studies by the trypan blue dye exclusion test, or fixed for light and electron microscopy. Biochemical and morphological findings of the present study showed for the first time that hydroxytyrosol and oleuropein inhibit mast cell degranulation induced by both immune and non-immune pathways. These results suggest that olive phenols, particularly hydroxytyrosol and oleuropein, may provide insights into the development of useful tools for the prevention and treatment of mast cell-mediated disorders.